title: Reactivity differences between 2,4- and 2,5-disubstituted zirconacyclopentadienes: a highly selective and general approach to 2,4-disubstituted phospholes.
abstract: Mixtures of 2,4- and 2,5-disubstituted zirconacyclopentadienes were obtained by the reductive dimerisation of terminal alkynes using the Cp2ZrCl2/lanthanum system. Reactions of dihalophosphines with these mixtures afforded selectively the corresponding 2,4-disubstituted phospholes and 1,4-disubstituted butadienes. A new series of phospholes was characterized by multi-nuclear NMR spectroscopy and X-ray analysis. A possible explanation for the observed selectivity was obtained from X-ray studies and DFT analysis of the intermediate zirconacyclopentadienes.
authors.affiliation: Institut de Chimie Moléculaire de Reims, UMR CNRS 7312, Université de Reims, BP 1039, 51687 Reims, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bousrez
authors.forename: Florian
authors.initials: F
authors.lastname: Jaroschik
authors.forename: Agathe
authors.initials: A
authors.lastname: Martinez
authors.forename: Dominique
authors.initials: D
authors.lastname: Harakat
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Nicolas
authors.forename: Xavier F
authors.initials: XF
authors.lastname: Le Goff
authors.forename: Jan
authors.initials: J
authors.lastname: Szymoniak